@ngrx/store

What is @ngrx/store?

@ngrx/store is a state management library for Angular applications, inspired by Redux. It provides a way to manage state in a predictable manner using actions, reducers, and selectors.

What are @ngrx/store's main functionalities?

State Management

This code demonstrates how to set up a basic state management system using @ngrx/store. The StoreModule is imported and configured with a reducer.

import { StoreModule } from '@ngrx/store';
import { counterReducer } from './counter.reducer';

@NgModule({
  imports: [
    StoreModule.forRoot({ count: counterReducer })
  ]
})
export class AppModule {}

Actions

This code shows how to create actions using the createAction function. Actions are dispatched to trigger state changes.

import { createAction } from '@ngrx/store';

export const increment = createAction('[Counter] Increment');
export const decrement = createAction('[Counter] Decrement');
export const reset = createAction('[Counter] Reset');

Reducers

This code defines a reducer function using createReducer and on functions. The reducer handles different actions to update the state.

import { createReducer, on } from '@ngrx/store';
import { increment, decrement, reset } from './counter.actions';

export const initialState = 0;

const _counterReducer = createReducer(initialState,
  on(increment, state => state + 1),
  on(decrement, state => state - 1),
  on(reset, state => initialState)
);

export function counterReducer(state, action) {
  return _counterReducer(state, action);
}

Selectors

This code demonstrates how to create selectors to read specific pieces of state. Selectors are used to derive data from the store.

import { createSelector, createFeatureSelector } from '@ngrx/store';

export const selectCounterState = createFeatureSelector<number>('count');

export const selectCount = createSelector(
  selectCounterState,
  (state: number) => state
);

Other packages similar to @ngrx/store

redux

Redux is a popular state management library for JavaScript applications. It is similar to @ngrx/store in that it uses actions, reducers, and a single store to manage state. However, Redux is framework-agnostic and can be used with any JavaScript framework or library.

mobx

MobX is a state management library that uses observables to manage state. Unlike @ngrx/store, which follows a more rigid, predictable state management pattern, MobX allows for more flexible and reactive state management.

vuex

Vuex is a state management library specifically designed for Vue.js applications. It is similar to @ngrx/store in that it uses a centralized store, actions, and mutations (similar to reducers) to manage state. However, it is tightly integrated with Vue.js.

README

NgRx

The sources for this package are in the main NgRx repo. Please file issues and pull requests against that repo.

License: MIT

Changelog

6.0.0-beta.3 (2018-05-12)

Bug Fixes

• build: Use default build for schematics (#1057) (355b12f)

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